Article I: On Lying

1177. DEFINITION. A lie is a locution against the mind with the intention of deceiving.

Here, whatever per se has the force of manifesting that which is false is called locution, whether it is done formally through words, or equivalently through gestures, nods, deeds. Locution is made against the mind when the external word is dissonant or discordant from the internal word or judgment. The intention of deceiving imports the will of so enunciating the false that it may prudently be believed by the hearer. Whence, if the intention of deceiving or of saying the false is absent, either there is no lie, or it is not imputable. Thus he does not lie who, joking, utters the false in such a way that the hearers cannot be deceived; nor he who affirms the false which he believes true. On the contrary, he lies who says the true which he thinks to be false.

Note. Some today think and intend to prove that the definition of a lie handed down by all up to now is defective, and that a lie must be defined: a locution against the mind with the intention of deceiving him who has a right of knowing the truth.1 There is no one who does not see that these Authors stand apart from the common opinion, which considers the relation of lying to be essentially toward the true or toward illuminating the intellect of another, but not toward the rights of the subject. Cf. Ami du Cl., 1912, p. 358. Yet it must be confessed with St. Augustine that this is "a most difficult and most hidden question" (Enchir., c. 18).

DIVISION. A lie is threefold: officious, jocose, pernicious.

OFFICIOUS is that which is made on account of one's own or another's utility. JOCOSE, that which is made for the sake of one's own or another's delight. PERNICIOUS, that which is made with unjust harm of neighbor.

To lying is referred: SIMULATION, "by which someone intends through an external deed to signify something other than he has in mind": whence it is called a lie of deed; likewise HYPOCRISY, which is the fiction of a sinner simulating himself as just (III, 171).

1178. PRINCIPLES. I. Every lie is intrinsically evil. For it is against the natural institution and end of locution, which has been given by God to men so that it may be expressive of the mind and conformable to it. Whence it is said (Levit., 19, 11): Do not lie, nor shall each one deceive his neighbor. And (Coloss., 3, 9): Do not lie to one another.

II. A lie, whether officious or jocose, nevertheless does not exceed venial fault. It is opposed only to truthfulness, which virtue, per se, does not oblige under grave matter (cf. n. 402).

III. A pernicious lie is, per se, a grave sin. It is opposed not only to truthfulness, but also to justice and charity, or even to other virtues which per se oblige under grave matter (2. 2, q. 110, a. 4). Whence it is said (Prov., 12, 22): Lying lips are an abomination to the Lord. And (Wis., 1, 11): The mouth that lies kills the soul. And it must be noted that he who has injured justice through a lie is held to restitution.